Field
This invention pertains to dechlorination. In particular it pertains to an improved sulfurous acid dechlorination method of chlorinated waters to increase sulfites, prevent SO2 gassing off, and off-setting monovalent chlorides in the treated water for land application.
State of the Art
As stated in EPA 832-F-00-022, September 2000 article entitled “Wastewater Technology Fact Sheet Dechlorination”; Dechlorination is the process of removing residual chlorine from disinfected wastewater prior to discharge into the environment. Sulfur dioxide is most commonly used for dechlorination and is the major focus of this fact sheet. Some dechlorination alternatives include carbon adsorption, sodium metabisulfite, sodium bisulfite, and hydrogen peroxide. Sodium metabisulfite and sodium bisulfite are mainly used in small facilities because these materials are more difficult to control compared to sulfur dioxide. Hydrogen peroxide is not frequently used because it is dangerous to handle (WEF, 1996).